


Universal Constant

by One_Hundred_Zeros



Category: Marvel Cinematic Universe, The Avengers (Marvel Movies)
Genre: Bucky is actually nice, Fix Everything, M/M, Post-Infinity War, Protective Stephen, Steve gets his redemption, major fix it, some spoilers for infinity war
Language: English
Status: In-Progress
Published: 2018-05-17
Updated: 2018-06-11
Packaged: 2019-05-08 06:57:42
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 9,732
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14688873
Author URL: https://archiveofourown.org/users/One_Hundred_Zeros/pseuds/One_Hundred_Zeros
Summary: “Mr Stark, I was wondering-” Peter takes a breath, “Do you know Dr Strange well?”Tony blinks, surprised. “No. Not particularly.” He purses his lips. “Why do you ask?”





	1. Ashes to Ashes

**Author's Note:**

> This is just me writing the ironstrange fic I want to see. A lot of self-indulgence here, and some Infinity War spoilers (you have been warned).
> 
> I don't remember all the details from the movie exactly, so drop me a note/comment/message if anyone picks up inconsistencies! Now, on to the story.

It worked. Tony knows it worked because all around them, people are suddenly appearing on the streets of New York, materializing in overturned cars and on mounds of rubble that had once been shops and office buildings. For a while, there is only a stunned silence, as half the human race reappears on ruined streets that had been covered in nothing but ash for weeks.

And then the noise starts, a slow rolling wave of disbelief giving way to cheering, crying. Tony sees people running to hold one another, couples kissing. There are strangers hugging like life-long friends, unwilling to let go, filled with gratitude just to see another human being again.

Tony turns away. He is filthy and tired, and there is an ache in his chest from where Thanos pounded him into a wall. Nothing feels broken, but the way it hurts makes him think that there is going to be a livid bruise spanning his ribs for a while yet. He heaves himself out of a small crater and looks around for the others. He sees Steve and Bucky hovering anxiously over the prone form of Thanos some distance away. Thor sits in the middle of the street, stormbreaker resting at his side. Slumped against his back is Bruce, unconscious from the exertion of being the Hulk.

Tony looks at his lax sprawl with a twinge of envy and is just about to boost himself over to join them when at his side, there comes a loud sizzling in the air. In a split second, Tony has his cannons raised and aimed before he can even think about it, heart thudding in his throat and adrenaline juddering through his system. The portal opens up slowly, its edges sparking with gold. Through it, Tony sees Titan again. Just the sight of the dead planet turns him cold, makes fear shudder down his spine. Even knowing Thanos has been defeated at his own hands, the bleak red landscape strikes something deep and hopeless in the heart of him, an instinctive lurching of his gut, half-remembered dreams surfacing in his thoughts.

A figure stumbles through the portal before any of his fears take root. Tony stares. There on the street stands Peter Parker, looking shaky and wide-eyed. He blinks as though lost, then his gaze lands on Tony and it hurts to see the way relief settles onto the boy’s features.

“Mr Stark.” He takes an unsteady step forward and it suddenly strikes Tony just how young the boy is - seventeen years old, loyal and brave and so very, very young. He doesn’t even pause to consider, just opens his arms and lets the boy sink into his hold. Alive. Thank god, he’s alive. Tony’s next breath comes out too close to a sob and he has to close his eyes for a moment.

“You’re okay, kid. You’re okay.”

It is only when the sizzling returns that Tony’s eyes snap open. The portal is closing again, and on the other side is the solemn figure of one Stephen Strange, face lighted by the crimson glow of an alien sun. They stare at one another for a long moment, the portal closing in on itself while Strange makes no move to step through. Tony feels a surge of panic, and for the second time in as many minutes, finds himself reacting before he can think. He surges forward, hands closing vice tight around Strange’s wrist. A part of him is already prepared to lug the man through by force if he has to, as though everything he has been through in this war against Thanos has suddenly shredded the last of his impulse control.

“Like hell you’re staying there.” Tony snarls. At his side, Peter gapes. The portal halts.

On Titan, Strange looks down at Tony’s hands around his wrist, the hold no doubt hard enough to grind bone. If it hurts, he makes no indication of it. Then his eyes snap back up, gaze bright and sharp beneath the shadow of his brow. The intensity of it makes Tony falter, suddenly unsure.

Not looking away, Strange takes a step forward, then another, and then he emerges onto the ruined streets of New York and into the light of their familiar sun. Yet he doesn’t stop walking, just keeps coming at Tony with that razor’s edge of his attention cutting and severe. It makes Tony’s throat run dry and for a wild moment, he thinks Strange is going to punch him or kiss him. Peter gives his shoulder an insistent tug, and Tony finds himself backing away, letting the man go. Stephen Strange smiles at this, a curious lilt to his mouth that is almost smug. Then he is sweeping past Tony and Peter both, striding through another portal that has suddenly materialized, golden and sizzling in the air.

Tony whips around to see the ruined staircase of the Sanctum Sanctorum before it closes, Strange’s red cape flaring out behind him. He takes a sharp breath and exhales on a curse. Fuck. Of course Strange could have opened up another portal on Titan just fine. All this just to make a point. Fucking show off. Tony runs a hand tiredly through his hair, the last dregs of adrenaline deserting him as quickly as it came.

“Mr Stark.” Peter seems to have regained his bearings and is now looking around the ruined streets of New York.

“What is it, kid?”

“Did Thanos- uh, cause _all_ this damage?” In the distance, a clean up crew has already descended, quickly and efficiently rebuilding New York as they have done time and time again.

“Mostly.” Tony chooses not to mention the part when Hulk picked up a telephone pole to use as a battering ram.

Peter whistles appreciatively. “Woah. Wish I’d been around to help with that.” Tony frowns.

“Better that you weren’t.” Tony isn’t about to see Peter running into danger again. The one time on Titan was one time too many, and he, for one, will be happy to see their friendly neighborhood Spiderman actually stay _in_ the neighborhood. He slings an arm around Peter’s shoulders, companionable. “Let’s get you back to Aunt May.”

 

* * *

  

New York patches herself back together and the world heals. For a while, people everywhere were shaky and uncertain. Passersby on the street became oddly nice to one another, and crime dropped steeply. The sidewalks filled up with people the way it hadn’t for months, and there was a peace. A nervous, anxious kind of peace. Even after the reunions and rejoicing, everyone was still on edge, still too raw from death and grief to resettle back into their old lives.

The healing is slow. One day, Tony sees a group of school children roughhousing in the park. At his favorite lunch restaurant, a young couple argues over a magazine. It is two weeks later when a snatch thief makes off with a businessman’s briefcase. FRIDAY lets Tony know that Spiderman is almost immediately on to the thief. By the time Tony turns up on the scene, the briefcase has already been returned and Peter is strolling down the streets, spiderman suit nowhere in sight.

“Good work there, kiddo.”

“Mr Stark!” Peter brightens instantly to see him, jogging up to where Tony is leaning against a lamppost in suit jacket and jeans. “Did you see that? He totally didn’t think I’d come from above.”

“Very impressive,” Tony agreed. They resume walking down the street together, shoulder to shoulder. Tony has not seen Peter since the day Thanos fell, giving him space to spend time with his friends and with Aunt May. The boy looks good, a bounce to his step that reassures Tony.

Two blocks down, Peter turns and asks: “Are you busy, Mr Stark?”

Tony raises a brow. “Right now? Or are you asking about my life in general?”

This makes Peter pull a face. “Aunt May works at a cafe nearby and I just thought…” He trails off, suddenly uncertain.

Ah. Tony coughs to hide how pleased he is. “If it’s lunch, I could eat.” And gladly, but he isn’t about to tell Peter that.

“Really?” Peter does a little half-skip. “That’s awesome! I’m finally gonna have lunch with Iron Man.”

Considering everything they’ve been through at this point, Tony really doesn’t think lunch should make Peter so excited. The cafe Peter leads them to is on the next corner, worn looking and nothing like those swanky chic stores that crowded every street. Save a few chips in its stone facade, it seems to have survived the recent devastation of New York.

Aunt May bustles out five minutes after they sit and kisses Peter on the cheek before taking their order. Peter laughs, the world’s most obliging teenager. He asks for a BLT and then recommends Tony the House Special. The menu describes it as some kind of bagel sandwich with too much grilled onion, but Tony doesn’t complain. He waits for May to disappear back into the staff area before digging the envelope out from his jacket pocket, pushing it across the table to Peter. The boy’s eyes widen, no doubt already noting the heavy cream paper and gold-leaf over his name.

“This is…?”

Tony makes a go-on gesture with his hands. “See for yourself.”

Peter plucks the card from the envelope, eyes going wide. “No way,” he says, more to himself than to Tony. It is an invitation to the Avengers’ Reunion Gala next week at the Town Hall, which anyone even tenuously related to the Avengers and Thanos is invited to.

Tony knows the event is nothing more than a showy way for the politicians to renege on their accusations and admit they were wrong when they tried to coerce the Avengers into accepting sanctions not so long ago. An elaborate sorry; we’re mistaken; thank you for saving our hides anyway. It makes Tony sick with anger - as though enough glitz and glamour could fix the fissure that had carved itself through the Avengers, their _friends._ He swallows the bitterness. Peter doesn’t know most of this and doesn’t need to. What happened was before Thanos. The world is changing now and even Tony doesn’t know where they’ll end up.

Aunt May returns with lunch and a plate of Lyonnaise potatoes, on the house. Peter shoves the envelope and card into his bag hurriedly, turning to grin brightly at her. The kid is an awful liar - the grin only makes Aunt May narrow her eyes at him. Thankfully she is too busy to interrogate him now, but she promises they’ll “Have a talk” later. Peter ducks his head sheepishly.

The bagel is good, and Tony finds himself starting to enjoy the heaps of onions when Peter suddenly looks up and clears his throat.

“Mr Stark, I was wondering-” The boy takes a breath, “Do you know Dr Strange well?”

Tony blinks, surprised. “No. Not particularly.” He purses his lips. “Why do you ask?”

Peter rubs thoughtfully at the back of his neck. “Well, he was the one who warned you about Thanos, and - I mean. You saw his portals and lassos and everything. I’ve never seen anything like that and I was thinking maybe you’d know how they worked.”

Tony does not, in fact, know how they work, and the thought of figuring them out has not crossed his mind. Even since Thor and Loki, Tony has conceded that there are things in this universe that science cannot yet adequately explain: Norse gods being one of them, now Stephen Strange is just another. Peter, however, has that glint in his eyes that Tony recognizes well, and somewhat warily, he sets down his half eaten bagel.

“Sorry kiddo, I’ve never heard of him before Thanos.”

“Then how-”

“He must have found me only because of the Avengers Initiative.”

Peter’s shoulders slump slightly. “D’you think I could… contact him?”

Right. Peter doesn’t know about the Sanctum Sanctorum, and Tony isn’t about to tell him. He hasn’t figured out what Stephen Strange does, but any man who is the guardian of an Infinity Stone and knows enough to herald Thanos’s arrival - well. Tony does not want to encourage Peter’s affinity for seeking out danger.

“I’m sure there’s something on the internet,” he suggests instead. “Guy like that isn’t exactly low key.”

“You’re right!” Peter looks instantly more energetic. “I should’ve tried that first.”

Tony smiles and hopes Strange isn’t the sort of guy who publishes the Sanctum’s address for anyone to find. He did seem a cautious man.

 

* * *

 

**Mr Stark,**

**I need your advice. It turns out that Doctor Strange is his real name and I was so rude when I suggested otherwise. How do you think I should apologize to him?**

**Sincerely,**

**Peter**

It is three in the morning when Peter sends him the email, and Tony reads it immediately because he happened to be awake. The message lands him somewhere halfway between a laugh and a groan. The boy needs to loosen up a little.

**Go to bed Peter.**

**I think he’s used to it.**

There is no reply for a few minutes, and then:

**Okay, Mr Stark. You should get some sleep too.**

Tony’s smile turns wry at that. He would, if the memories left him alone. These days when he is alone with his thoughts too long, they invariably return to scenes of Titan and the sight of people disappearing around him. When he is somewhere between asleep and awake, the dreams take on a curious life-like quality, and ash sweeps across everything. He sees his parents disintegrating, Pepper, the Avengers, himself. From ashes to ashes, dust to dust.

He rubs tiredly at his eyes. In his mind, he hears Stephen’s voice, low and rough across the landscape of his memories. _Tony, there was no other way._ Tony wonders what he saw in the fourteen million futures to come to this conclusion. _No other way_ _._ Fourteen million data points, a matter of statistical significance, p less than zero point zero five. Tony tosses his phone aside.

Ever since Peter’s questions that afternoon, the thought hasn’t left his mind that he knows nothing about Stephen Strange. Despite his earlier claim that someone like Strange was sure to stand out, the truth remains that he had _not_ heard of sorcerers or Sanctums until they found him.

Abruptly annoyed by his own ignorance, Tony heaves himself over to his work terminal. He starts a search through the major news sites for Strange’s face, and while the facial recognition algorithm does its work, he pulls up Google and enters “Doctor Stephen Strange”.

He doesn’t know what he expects, but the first results turn out to be publications in major academic journals. Stephen Strange, principal investigator. A pioneer in neurosurgery techniques and unrivalled in aptitude. A _scientist._

Tony doesn’t understand half of what the papers discuss, so he turns to the other links. These are all news headliners from not so long ago, and Tony skims them rapidly.

_What will become of Stephen Strange?_

_World renowned neurosurgeon no more._

_He saved thousands of lives, now who can save his?_

And further down, an early article by the New York Times: _Doctor Strange in car accident, outcome uncertain._

Tony opens that up. It is a short article, just a bare statement of facts. Doctor Stephen Strange, neurosurgeon, unrivalled in aptitude. Car crash from speeding. Great loss to the field. Tony reads it again, and then again. Something about it strikes a little too close to home, the outline of the plot too familiar. If he squints, he sees underneath a different story, one about missiles and Afghanistan.

The facial recognition search pings, listing off results in terms of closest match. The first few are scenes from their battle against Thanos, caught by security cameras around New York. Then comes the professional photo that the papers have been using, Strange staring in the camera, his mouth wide and unsmiling. It isn’t a good likeness of the man, although Tony cannot quite put his finger on why.

It is the next picture that makes Tony pause. It was taken at a charity gala, Tony knows because that’s the kind of event he used to frequent. The photographer had caught Strange at a perfect moment, just as he was turning to smile at someone. The image is clear and crisp, but the softness about the man’s eyes is stunning. He looks younger, although the picture isn’t all that old. Tony stares at it for a long moment, trying to imagine what Stephen Strange might have been once. He thinks he knows: rich, self-assured, callous and careless.

Tony switches the display off, suddenly tired. There is a heaviness tugging at him that is only partly exhaustion. He shuffles over to his bed and asks FRIDAY to wake him up at noon. The AI murmurs a low affirmative, but Tony is already falling into sleep.

The memories rush to greet him - in his mind, the dead planet of Titan stretches empty and barren under a rust red sun. He is the only one around this time, but there are a thousand sea green butterflies wheeling through the sky. When they speak, they speak with Stephen’s voice and they tell him: _Tony, there was no other way._

He still wonders what that means.


	2. Making Amends

**Notes for the Chapter:**

> Thank you to everyone who commented on the last chapter! I'm sorry I don't always know what to reply, but know that your comments made me really happy ;_;
> 
> Also a shout-out to Gureen for pointing out a (major) mistake in quotes, which has now been fixed.

Once, years ago, Tony had asked Thor about Mjolnir.

“She is my weapon, of course,” the mighty Asgardian had bellowed in his mighty voice, picking it up and swinging casually.

Tony had waved a hand, young and dismissive. “No, no I get that. But how does she summon the storms?”

Thor levelled him a baffled look. “Why, Man of Iron, I was under the impression that humans know well how the weather changes, is that not so?”

“Yes, of course, but I was asking about your hammer, Thor. How does Mjolnir do it?”

“Oh, I see!” The Asgardian nodded his head in understanding. “Mjolnir works the same way, creating a center of low pressure with high-pressured air around it.” He circled one hand around his fist. “I don’t understand your science well enough to explain it to you in those terms.”

Tony squinted. He didn’t think Thor understood at all. Mjolnir was an Asgardian weapon with mythical capabilities beyond human science and engineering - Thor’s explanation was lukewarm at best, and Tony came away none the wiser about anything. He huffed in resignation and gave it up as a lost cause. Even if Thor really did comprehend the workings of Asgardian weaponry, he was turning out to be the worst candidate for translating magic into science.

 

* * *

 

The story the media spins them is an easy one: two friends, brothers in arms, forced to turn on one another at the instigation of the government. Both acting out of love and gravely misunderstood, eager to mend bridges once a greater evil appeared. A tragedy transmuted into triumph. The Avengers now reunited in glory.

Tony stops reading the papers after the first one.

In defense of the reporters, this is the story the Avengers are actively trying to promote. Tony and Steve now make all their press appearances together, bantering like best friends and taking pictures with their arms around one another. Tony doesn’t know what Steve thinks of this, but the pretense throws everything off-kilter, like walking into a room where all the furniture has been moved three inches to the left. Familiar, but not familiar enough, both of them always at risk of walking into a chair, or a table, or a fucking landmine.

For the most part, it works out fine because Tony and Steve don’t hate each other. Hating each other would have been easy, but they have weathered too much to settle for easy. In the week leading up to the Gala, there is a sudden surge of interviews as various news sources scramble to stay up to date. Like a season of Keeping up with the Avengers, Tony told FRIDAY once. The AI didn’t find it very funny.

It is a reporter from the Washington Post who first brings up Sergeant James Barnes, perhaps eager for a soundbite or just foolhardy. Tony and Steve are both familiar enough with the press not to react in any obvious way, but there is a tightness around Steve’s eyes when he replies.

“Bucky is a dear friend of mine,” he says, leaning forwards in his seat, blue eyes earnest and compelling. America’s golden boy pleading with listeners to agree. “I know he has done things people may find hard to forgive, but believe me when I say he was unwillingly used to malicious ends.” Steve glances at Tony, then adds, “The past hurts him as much as it does all of us, but he _is_ working to make amends.”

This is Tony’s cue to voice his support, he digs his fingers into his thighs. “We are all doing our best to set things right again.”

It isn’t much, but it seems enough because their interviewer returns to questions about Thanos and their role in bringing him down. Privately, Tony has to admit that Steve gave a good answer, expertly diverting another scrutinizing gaze. Resentment curdles in the back of his throat, bitter like the taste of ash.

Tony slips out of the room the moment the interview is concluded, leaving the last pleasantries to Steve. Outside, Pepper waits in a sharp white suit and five-inch Ferragamo heels. This is her battle uniform and is all she wears lately. She’s here to debrief the reporter as she does after every interview, so she only has time to whisper a quick “Good work” before marching past Tony into the meeting room, her heels clicking evenly across the tile. Today, she is the CEO of Stark Industries, and the knowledge shakes something loose within him. Again and again, Pepper changes herself at every turn for Tony Stark’s convenience.

Tony hurries down the corridor in an effort to distance himself from that thought. Even then he isn’t fast enough, he hears the rapid pounding of footsteps before Steve draws level to him.

“Hold on, Tony. Wait!” Steve makes to grab Tony’s shoulder, and Tony reluctantly grinds to a halt just to avoid the touch. 

“Yes?”

“It’s about Bucky.” 

“What about him?”

It is a testament to what their relationship has become that Steve doesn’t even flinch at the tone. “I just wanted to ask when Bucky’s restrictions are going to be lifted.”

Of course, Tony should have seen it coming. “We’ve been through this.” He rubs at his eyes and struggles not to let the frustration bleed through. “No one knows how much hold Hydra’s brainwashing still has over Mr Barnes, so we owe it to the public to watch over him in Stark Tower until a time he proves himself trustworthy.”

“And when will that be, Tony?” Steve gives him a searching look. “We can’t keep him detained in this building forever.”

Sometimes Tony thinks he should make recordings of himself for Steve to play on repeat, it wouldn’t be so different from their conversations now. He spreads his hands. “I am sure we’ve mentioned that Mr Barnes can always consent to let us examine his arm and do a temporal imaging of his brain. The procedures are non-invasive, of course, but they would go a long way reassuring-”

“No.” Steve draws himself to his full height, chin tilted up so that he can stare down the length of that perfect nose. “We are not letting _you_ perform any procedures on Bucky.”

“Perhaps you should let Bucky decide that for himself.”

Steve shakes his head slowly. “Tony. Surely at this point you must admit that you are the only one who wants these restrictions in place.”

Tony narrows his eyes. _The only one?_ All the Avengers know how skittish public sentiment has been about the former Soviet assassin - the only reason a full inquiry hasn’t been demanded is because they are heroes in the wake of Thanos and enjoying an unusual spate of good will. Of course Steve chooses to ignore this. He is a soldier through and through. Tony remembers now why compromise had been impossible during the Sokovia accords - you cannot compromise with someone for whom every confrontation is a battlefield. He takes a step forward, irritation seething under his skin.

“Is this what you meant when you talked about making amends?” he asks. “I must admit, Rogers, I am not quite feeling the spirit.”

There is a flash of fury in Steve’s eyes, lightning fast and gone just as quickly as it came. It makes Tony smile to see him shaken, to see the man beneath all that star-spangled goodness. 

“You’re one to talk,” Steve isn’t spitting but it is a close thing. “If we’re judging the blood on his hands, Bucky is a better man than you are a hundred times over.”

Tony stills. He had forgotten. Steve, America’s golden boy, is so steeped in virtue that he knows nothing about guilt or regret. A man casually cruel in his righteousness. Resentment burns up Tony’s lungs, the memory of missiles falling out of the sky shaking through his bones like the aftershock of impact. Tony steps away.

“I’m leaving,” he announces, spinning on his heel.

Disengage, he tells himself as he walks away. He must disengage. There is a part of him that fears Steve will come after him, to push and pressure as only he can, but maybe even Steve has sensed the knife’s edge on which they tread because for once, he lets Tony go.

It is an unexpected mercy. Tony is almost grateful.

 

* * *

 

Tony doesn’t have a drinking problem - not anymore - but he disappears into the pantry to pour himself a shot of whiskey. It is not nearly enough to help him forget, but the burn of alcohol doesn’t come with the memory of ash and dust.

On the kitchen counter is a small array of abandoned mugs, the collection having expanded since everyone returned. There are two mismatched coffee cups drying on the dishrack. Tony stares at the pair unseeingly as he goes through the motions of pouring his drink. One of them is in red, white and blue, the color scheme Steve’s fans seem to think he loves. The other is a tasteful gray with a single white star. It’s new, but Tony knows who it belongs to.

Suddenly, the empty pantry feels too exposed, anyone could walk in and see him standing here with that haunted look he wears so well. He can imagine the pity in their eyes - or worse, the possibility that there would be no pity at all, only silent accusation.

Tony shoves the bottle back in its place and leaves the pantry as quickly as he can without feeling like he is running. It seems that this is what he always does - turn his back on uncomfortable situations. Maybe Steve was onto something. Maybe Tony is the one who doesn’t want to give Bucky a chance to change.

He breathes a sigh of relief the moment the door to his room closes, pathetically grateful for the privacy. Here, where there are no reminders of Steve and Bucky, the drink doesn’t look so inviting anymore, so Tony sets the glass down on his bedside table and meanders over to his desk. The engineering department had sent him new blueprints to look through, and it is the kind of detailed work that always takes his mind off things better than alcohol.

The desktop screen flickers to life. Tony pauses. On the display, a dozen search results of Doctor Strange are overlaid across one another. He had forgotten to close them last night, and now the picture of a young Stephen looks out of the screen, smiling at a corner of the room.  Instantly self-conscious, Tony moves reactively to close all the windows as though to hide an indiscretion, but then an unexpected thought stops him. The New York Times article is still open, and Tony finds himself reading it again for what feels like the hundredth time, sentences unfolding in predestined patterns.

Doctor Stephen Strange, neurosurgeon, unrivalled in aptitude. Car crash from speeding... Tony’s eyes drift back to the start of the article. _Doctor Stephen Strange, world renowned neurosurgeon-_

Tony springs out of his chair and dashes for the elevators.

“FRIDAY,” he speaks urgently. “Prepare my car. Destination 177A Bleecker Street.”

He makes himself take deep breaths on the way down Stark Tower. It is just an idea, he still needs so many people to cooperate, and even then there is no guarantee that anything will turn out the way he envisions, but- he taps a foot impatiently- but this is the best idea he’s had for a while.

The ride is a short one, but the anticipation makes it drag on forever. Tony leaps out the door the moment the car slows to a halt. In front of him, a row of brownstone houses sit ordinary and unremarkable. For a moment, Tony entertains the possibility that he is mistaken, that the Sanctum has moved, or disappeared, or was never here in the first place. Then he shakes his head and tells himself to stop dallying. Marching up, he raps smartly on a blank stretch of wall between two houses, sparing only the briefest thought for what the passersby must think to see this crazy man.

There is no reaction, and Tony frowns. He knocks again, harder. Then, when still nothing happens, he lifts his head and prepares to holler for the Sorcerer Supreme.

“For the love of all things good and holy, shut up.”

Tony blinks. A door has opened where none had been, and standing on the threshold is Stephen Strange, frowning impressively.

“Oh,” Tony says. “You _are_ in.”

“I was in the middle of my daily yoga and meditation.” Stephen steps aside to let him through. “It’s never nice being interrupted when in a state of pure consciousness.”

Tony stops and squints. “Yoga. Really.”

“No.” Stephen’s mouth twitches upwards in a smile. “If you must know, I was in Nepal when Wong told me you were knocking. Now _he_ doesn’t like being interrupted when watching Beyonce’s concerts, so I offered to get the door.”

“Nice of you to do that.”

Stephen shrugs. “It’s no trouble.”

They enter what looks to be a library, the shelves lined with old books and curious artefacts. Tony tries to read the titles as they pass, and experiences a momentary disorientation when he realizes that he doesn’t recognize the language.

“Sanskrit,” Stephen explains. He drops into an armchair and gestures at the one opposite. “Please.” Tony takes a seat. From across the room, the red cloak floats itself over to settle around Stephen’s shoulders. Stephen laces his fingers together. “So, Tony. What can I help you with?”

Briefly, Tony considers building up to the idea slowly, but then he takes in the quiet expectation on Stephen’s face and decides that no, Stephen wouldn’t appreciate his dithering.

“You are a neurosurgeon,” Tony says, doing his best to sound sincere. He isn’t here to mock.

“Were.” The smile has slipped off Stephen’s face but his posture stays relaxed.

“Still a doctor though.”

“Hm. I assume you have a point?”

Tony leans forwards. “Say, hypothetically, that you are asked to supervise a medical procedure. You would be able to understand what you see going on - and identify any causes for concern.”

“Yes.” Stephen curls his hands into fists and slides them under his cloak. “But I wouldn’t be able to correct any mistakes or take over the work.”

“That is fine, there won’t be any.”

“Confident,” Stephen murmurs. He stares at Tony for a long moment. “This is about that man, Captain America’s friend-”

“James Barnes.”

“-Sergeant Barnes, isn’t it?”

Tony wants to look away. Stephen’s gaze is too keen, too steady, it feels as though the man can strip away all the posturing and see every terrible thing Tony has ever done. Tony runs a hand down his face and almost laughs. What is he thinking? Of course Stephen knows all that, knows fourteen million different permutations of Tony Stark and every mistake he can possibly make.

“Yes,” Tony admits wryly. “I’m afraid Captain Rogers doesn’t trust me to examine him alone.”

A pause, then: “Alright.”

Tony jerks up in surprise. “Come again?”

“Yes, alright, I will supervise the procedure.” Stephen says it like it is the easiest thing in the world. Tony frowns, disbelieving. It is never this simple. "Although," Stephen raises a hand, “I _do_ need Sergeant Barnes to give his full consent to the procedure, including my participation.”

This is hardly the most unreasonable request, Tony feels his eyebrows lift. He had expected Stephen to ask for more. “I would have made sure they were fully informed anyway.”

Stephen makes an impatient gesture. “That’s not it.”

“No?”

“No. Tony, there is no they. I don’t need to know what Captain Rogers thinks, and I don’t care whether you tell him at all.” Stephen scowls. “This isn’t about him, which means he can ship his consent and concerns to Dormammu for all the difference it makes.”

Tony almost smiles, but the sharp intensity has returned to Stephen’s eyes. He isn’t joking. This is the man who fought Thanos on Titan, the man who once turned to Tony and said _there was no other way._ But Tony knows something that Stephen doesn’t: Steve and Bucky are always _them._ Tony made the mistake of assuming otherwise once, and it tore the Avengers apart. He would sooner return to Afghanistan than risk that again.

All the same, Tony meets Stephen’s gaze as confidently as he can. “No Captain America needed, got it.” 

Frustration flares in Stephen’s eyes. Of course he sees the lie for what it is. Tony wouldn’t blame him if he decides to rescind his agreement now. After what he gave up for Tony, honesty is the least he could ask for. It is just unfortunate that Tony isn’t very good at treating people the way they deserve.

But Stephen doesn’t point out the lie, just closes his eyes and sighs. “So long as you understand,” he says at last. He gets to his feet.

They walk back to the front entrance in silence, the space between them filled with only the faint hum of magical artefacts. At the door, Stephen bids him a solemn farewell, stilted and uneasy. It sounds so wrong that Tony almost blurts out a question about yoga to break the tension, but then he sees Wong wandering into the foyer looking faintly disapproving, and any attempt at levity instantly evaporates from his thoughts.

“Thank you,” he says, more honest than he wants to be. Tony means it for many things, not just agreeing to supervise the procedure, but he can’t find the words to describe the full length and breadth of his gratitude.

Yet inadequate as they are, it seems that Tony finally said the right things because Stephen’s gaze softens from its harsh tautness. In the clear light of New York’s mid afternoon sun, Tony is suddenly reminded of the young man at the charity event, gazing at someone off camera. His breath catches in his throat.

“Anytime.” Stephen smiles as though he knows a secret he isn’t going to share. “Anytime at all.”


	3. Black Box

**Notes for the Chapter:**

> Once again: A gigantic thank you to everyone who commented on the last chapter! I love y'all and I read everything multiple times.

Tony returns to Stark Tower to find the other agents having an impromptu games night in the lounge. Even from out in the corridor, he could hear the excited shouts and groans of disappointment, which is why he is entirely unsurprised when he joins the team and sees Nat destroying Clint at Monopoly while Sam and Rhodes duke it out on the playstation.

“Tony!” Bruce calls out to him almost immediately, waving him over with one hand. “Are those tacos?”

“Hey buddy.” Tony holds out his box of takeout Mexican food.

Bruce digs in eagerly, shoveling half a beef taco into his mouth before saying, “Where’ve you been? I looked everywhere for you before FRIDAY told me you went out.”

“Oh, here and there.”

The best part about Bruce - the thing that makes him Tony’s science bro and best friend - is that he knows when not to pry. He doesn’t press Tony for details, just brushes it off and shrugs. "How about a game of Scrabble?"

The two of them pick their way through the scattered bean bags and empty take-out boxes, doing their best not to trip over any sprawled legs. The board games are stashed in the tv cabinet and Tony helps Bruce look around for the Scrabble box. It is a while before they manage to dislodge the set from where it is wedged in the back and clear out space on the carpet to set up their food and game.

Bruce thrashes Tony solidly in the first couple of rounds as a matter of course, then just before they start their third round, Clint wanders over looking morose. “Nat won my entire tub of gourmet popcorn,” he tells them, settling down on one side of the board.

“Oh. Sounds rough.” Bruce pats him on the back. “Want to join us instead?”

The offer cheers Clint up immediately and Tony tries not to laugh when Bruce ends up winning again in six turns. He managed a last minute _quixotry,_ which was impressive and made Clint overturn his row of tiles in exasperation.

“Another round?” Bruce asks, gathering the letters back into their bag.

“I’m good.” Tony waves a hand and picks up the empty taco box to dispose of in the pantry. The little kitchen area is dimly lit, and on the side opposite the lounge, a pair of sliding glass doors lead onto the balcony. Tony hears the laughter first before he sees Steve and Bucky leaning against the balustrade, heads bent close in quiet conversation. Steve has a hand on Bucky’s arm, the gesture oddly intimate. Tony jerks his gaze away sharply, a mix of mortification and resentment roiling in his chest. He had planned on fielding the proposal of Doctor Strange supervising Bucky’s procedure the moment he saw the two of them, but doing so suddenly felt like an intrusion. He swallows uneasily.

There is a packet of popcorn kernels on the kitchen island, the kind sold three to a batch at the corner store - not really gourmet stuff, but Tony idly throws it into the microwave anyway. “FRIDAY,” he says, keeping his voice pitched lower than the rapid fire of popping kernels. “Let Captain Rogers and Sergeant Barnes know I have a proposal regarding Sergeant Barnes’ physicals. We should meet to discuss it, whenever they have time, but preferably as soon as possible.”

“Message acknowledged. Would you like me to send it now?”

He does not look at the balcony again. “Schedule it for ten tomorrow morning. Thank you, FRIDAY.”

“You’re welcome.”

Tony stops the microwave before it starts beeping and almost burns his fingers trying to extract the bag of popcorn. His sacrifice, however, is appreciated because Clint gives a great whoop when he appears in the lounge carrying the large bowl in the crook of his arm.

“My hero!” Clint exclaims, swooning into Bruce’s lap.

It’s ridiculous, and it makes Tony suddenly, fiercely glad. There had been a time when he thought he had lost these friends forever, yet here they are, sprawled on bean bag chairs and chattering lazily as though they’d never left, fitting themselves back into Tony’s home and Tony’s life.

The realization almost overwhelms him: the team _is_ mending itself back together, as slowly and surely as New York itself. Now the only piece left is Steve, and with Steve comes Bucky. The idea doesn’t make Tony happy, not exactly - his parents’ death is still a memory like a live-wire, too raw to overcome - but he is determined to try, and Stephen Strange has given him hope that it can be done.

“Hey, you okay?” Sam leans over the arm of the couch to poke Tony in the side. “You were all spaced out for a moment there.”

Tony smiles. “Yeah, I’m good."

* * *

 

 

He should have known better than to be optimistic about anything when the universe has always been hell-bent on making Tony Stark’s life difficult. Just before noon the Monday after their games night, all their communicators start pinging urgently with a slew of emergency summons.

“Hostage situation at Times Square?” Nat exclaims, already running for the helicarrier on the rooftop. Disbelief colors her voice, and she isn’t the only one.

Tony himself has asked FRIDAY to verify the alert independently. It must be a false alarm - crime rates have been so low, and mostly limited to petty theft and minor misdemeanors.

“I have the security camera feeds from around Times Square,” FRIDAY says in his ear.

“Send them to me.”

Tony ducks into the helicarrier to see everyone already assembled. Unlikely as the situation is, no one is taking chances. Even Steve is there, fully suited and tension in every line of his body. He gives Tony an inscrutable look, and Tony cannot tell if this means he’s read the message or not.

An icon flashes in the peripherals of his visor, and Tony enlarges the video. Then he frowns.

“Tony?” It’s Nat.

“Let’s go. I’ll brief you guys on the way.”

The black and white videos continue to flicker between six different perspectives, showing the square deserted of people, a wreck of overturned chairs and food carts and abandoned belongings. In the center are four masked men, armed with rifles and guarding a large square box. It is solidly black from all angles, and Tony cannot begin to guess at what it contains.

“No markings?” Clint asks, tightening and re-tightening his bow string.

“I think so. The video quality is too poor.”

“I’ll take a first look before we deploy.” Clint gives a sharp nod, “If there’s anything to see I’ll catch it.”

Steve lifts his head from where he and Nat are bent over the flight controls. “Bruce and I will evacuate the civilians in the surrounding area.”

“Good idea.” Tony zooms in on the scene, squinting to make out the background details. “Clear out the Hilton first, I see too many people through the windows, it’ll make them easy targets.”

Even as he says this, Tony frowns. The whole situation feels off, a nagging sensation in the back of his mind that won’t leave him alone. The criminals have made no demands, and threatened nobody. It is only a hostage situation insofar as it has the potential to _become_ a hostage situation.

“Considerate criminals.” He shakes his head. “What do they want?”

“We’ll find out soon,” Nat announces over her shoulder. “We’re coming up above Times Square. Clint, get ready.”

The box is as nondescript in Clint’s eyes as it was in the video feeds, and having no better information to work on, the team drops down right over the criminals. Cap takes out one of the men with his shield before the guns come up blazing, bullets ringing in every direction.

“I’m going for the civilians!” he shouts, he and Bruce diving for the stores circling Times Square.

Tony grunts an affirmative, aiming his repulsors at one of the gunmen. The twin shots clip the man on the shoulder and he staggers back, momentarily loosening his hold on his rifle. Nat takes her opening instantly, aiming a punch at his wound so that he lets out a strangled cry of pain. The man tries to dislodge her with a series of violent kicks, but she only tightens her hold, digging her fingers in until he howls and the gun clatters out of his grip. In the next moment, their fight turns into vicious hand-to-hand combat, and Tony knows Nat can hold her ground.

Clint has pinned another one of the criminals with two arrows through his feet. The guy is tugging roughly on their shafts, fingers slick with blood.

“Run!” he hollers just as Tony turns his attention to the last man standing. “Go! Go-” He chokes off, biting his own tongue when Sam aims a heavy blow at his temple with the butt of his gun.

The fourth criminal breaks into a sprint, sparing barely a second glance at his comrades as he escapes down seventh avenue.

“I’m onto him!” Tony shouts, firing the blasters of his suit to run the man down. He is small and swift, and - Tony realizes as he hurtles closer - _she_ is a woman. Having tossed aside her gun, she now has no way to retaliate. If Tony can just corner her at the police barricade further up the street-

The woman dashes for the side of a building and before Tony can react, disappears completely into the brickwork.

“Fuck, fuck, fuck.” Tony scrambles to raise his repulsors, throttling them to full power in order to come to a halt before he crashes into the wall. A good thing too. When Tony presses his palm to the brick, he finds it firm and solid - not a hologram or an illusion.

“What the hell.” He boosts himself into the sky. Looking down from above the building, he sees - impossibly - the woman sprinting out on the other side before disappearing into the next building, running through obstacles as though they are thin air.

This is bad. Tony can follow her, but catching her will be much harder. In close quarters, the woman has the advantage of being able to disappear behind walls, and the Iron suit just doesn’t have that kind of maneuverability - not without running holes through a city block. He dives after her, hoping to catch her when she is exposed on the street, between jaunts through buildings.

The woman looks up just as he closes in, and for a moment, Tony almost thinks he got her, coming so close the whites of her eyes are visible around dark pupils. Then the woman ducks and too late, Tony sees the small gun in her hand, hidden under her coat until a moment ago. The street is too narrow for him to swerve, but Tony tries anyway, narrowly missing a streetlamp only to ram into a fire escape. The woman doesn’t flinch, carefully aiming her weapon, the muzzle locking on to his arc reactor. Maybe the bullet won’t be strong enough to shatter it, Tony thinks wildly. Maybe-

Something red rushes up the street and twists around the woman’s limbs, knocking the gun from her grip.

The Cloak of Levitation.

Utterly improbable, but there it is. Tony allows himself to stare at the struggle for half a second before he once again springs into action, aiming his repulsors to fire. He manages one good shot into the woman’s thigh before she finally stumbles out of the cloak’s clutches and dives into the next building, disappearing completely from view. Tony swears. He throttles up his engines and is just about to launch himself into the air for a second attempt when the portal opens up in the side of the building, golden light sparking against Tony’s visor.

“This way!” Stephen beckons from just inside, and Tony sees past him to the line of portals leading straight through the building and out the other side. “Hurry!”

There is just the slightest strain in Stephen’s voice, a tremble to his hands from the effort. Tony doesn’t need to be told twice. He lunges into the portal, and then the next, and then the next, their sizzling sparks loud in his ear. Then suddenly, he is out above the street, pivoting just in time to see the criminal herself stumble out. She clearly isn’t expecting Tony to be waiting for her, and her eyes widen in horrified realization even as Tony’s repulsors fire two sonic pulses straight into her face, dropping her where she stands.

The woman collapses to the ground with hands over her ears, a cry choking off at her lips. She squints venomously up at Tony through her sweat-matted fringe, but otherwise doesn’t seem capable of much else. Deciding that it’s safe enough, Tony extracts a length of vibranium chord from his suit and deftly strides over to bind her wrists behind her back, not caring much about being gentle.

He hears the portal opening but doesn’t look up from his task until he trusts that the woman is too tightly bound to attempt any more tricks. Then he gets to his feet, dusts off his suit, and finally turns to face Stephen.

“Tony.” Stephen nods and gestures at the woman. “Thought you needed a little help there.”

It takes a moment before Tony manages to speak past the tightness in his throat. “Yes,” he says. “Thank you.”

"It’s no trouble.” Stephen bends over the woman, running a hand through the air over her, golden threads of light delicately sweeping across the prone figure.

“Did Fury call you in?”

Stephen smiles thinly. “Your director doesn’t know of me - I think. But, what kind of sorcerer will I be if I can’t respond to emergencies in a timely manner?”

Tony huffs a reluctant laugh. “Fair enough.”

At last, Stephen seems satisfied with his examination and climbs back to his feet, the golden threads still sparking in his hands and up his arms. “Tony,” he says, and then he steps closer, something tense in his expression that is made worse by the creases on his forehead. A hand comes up to rest against the back of Tony’s neck. “I’ll leave her to you,” he says, and it’s a perfectly reasonable statement except that it feels as though he _means_ something entirely different.

“Stephen-”

Tony doesn’t know what he was going to say, probably something stupid like: “You saved me again. Why?” but he doesn’t get the chance because in the next moment there comes a cry from further up the street.

“Tony! Watch out!” It’s Steve, sprinting at them, legs a blur, sun glaring off his shield as he draws his arm back ready to throw.

“Stop!” Tony lunges. “Steve stop!”

The shield flies, a disc of merciless vibranium metal, the strongest element in the world. It clips the side of Tony’s helmet, and Tony whips around in time to see it impact the building wall, burying half into the brick. The collision makes the shield ring, a high resonant tone that rattles his teeth. At his feet, the bound criminal huddles into herself, wild eyed in fear.

Stephen has disappeared.

“Tony, are you okay?” Steve huffs as he draws level. “That man-”

Tony whirls on him. _“That man_ was helping us,” he hisses.

“But the light-”

“Is his ability! Do you never think before you act?”

Steve’s shoulders drop. “Oh,” he says. “Tony, I didn’t know.”

Tony sneers. “Of course not.” He takes a breath, forcing his fists to unclench. The adrenaline is still lurching uncomfortably through his system, making him feel sick from- from fear. He had been afraid. He turns to the criminal.

“Let’s get her to the helicarrier,” he says. “Then check your email.”

Steve presses his lips into a thin line, but he nods. “Okay.”

 

* * *

 

Back at Stark Tower, they take time to clean themselves up and make their reports to Fury before the confiscated materials are handed over to Tony and Bruce for analysis, a contradictory mix of state-of-the-art tech and crude rifles and the unmarked black cube. The incongruity of it all gnaws at Tony and it is only more aggravating because he has no good reason _why,_ just a bundle of vague misgivings about the whole incident from things that didn’t add up.

He glares at the little gun the woman had almost shot him with. “You first,” he declares, then looks a Bruce. “Do you want to start on the box?”

Bruce looks worried and for a moment it seems like he is going to comment on it, but then he just shakes his head and says, “Yeah, okay.”

They carry the items off to their own benches and soon the lab is filled with low humming and whirring from various machines running their analyses. Tony almost forgets about Steve for a few good hours, but then there comes a knock at his lab door and Tony looks up to find the Captain waiting in the corridor and the sky dark outside his windows.

“We got your message,” Steve says. He is holding a paper bag that he passes to Tony. Inside is a cup of ice custard, which is probably meant to be an apology but Tony just passes the bag on to Bruce without touching it. He isn’t so easily bribed.

They head over to the pantry where Bucky is already waiting for them, his own ice custard half finished in his hands. He looks up when they enter, and there is wariness in the way his eyes follow Tony across the room.

“All assembled, I see,” Tony says wryly. He doesn’t blame Bucky for the caution, even now his grief runs close to the surface of his thoughts and threatens to surge forth at any moment.

Steve takes a seat next to Bucky and looks expectantly between them both. “You said you have a proposal about Bucky’s physicals?”

“An idea,” Tony nods, taking the chair opposite them both. “It is clear that we must be able to guarantee that Bucky is free from Soviet brainwashing if he is to escape public scrutiny, or if the government starts making new accusations later on.” Tony turns his hands palm up. “But on the flip side, you don’t trust me to carry out the scans - no don’t argue. You know that’s true.”

Steve scowls but he closes his mouth on the protest.

“So my proposal is this: I conduct the procedure, but I will be supervised by a neurosurgeon who can, presumably, stop me if he identifies a risk.”

“You said the scans are going to be for Bucky’s brain _and arm.”_

Tony lifts a finger. “That’s true, but I don't suppose you have any objections to Bruce supervising that? Besides, you said the Wakandan princess - Shuri - has already conducted her own tests and fitted him with his new arm, so I don't expect to find anything worrying.”

Steve has his lips pursed, but he gives a terse nod.

“Good.” Tony makes a few quick taps on his tablet. “In that case, it’s really only his brain functions that need to be examined - make sure there are no lingering effects of brainwashing or trigger sequences or other gifts from mother Russia.”

Steve crosses his arms. “Do you have someone in mind?”

Tony slides his StarkNote over the tabletop. “Doctor Stephen Strange. Formerly a world renowned neurosurgeon. He can’t work anymore, but you won’t find anyone with greater expertise.”

Steve looks up sharply from the screen. “This is that man from today.”

“Yes.”

“He didn’t look like a doctor.”

“Well, that’s not his job now.”

Steve squints. “Why not? If he’s so good, why would he leave?”

“For no reason that needs concern you,” Tony snaps. His own fierceness surprises him. Stephen’s car accident is no secret, but it is a- vulnerability, almost. Like his own memories of Afghanistan. The thought of just telling Steve doesn’t feel right. It isn’t something Steve needs to know, and it’s definitely something he doesn’t _deserve_ to know.

Steve clearly doesn’t agree. He draws himself up and scowls. “This has _everything_ to do with Bucky!”

"Obviously."

"So-"

"So the only thing that  _should_ concern you is that Stephen Strange is a good doctor.”

“And your friend.” Bucky leans forward across the table, dark gaze intent. This is the first time he’s really spoken to Tony, and the sound of his voice is almost startling.

Tony frowns. He doesn't know what Bucky wants to hear. Is he more or less likely to trust someone who is Tony’s friend? And more than that, _is_ Stephen his friend? They’re not buddies the way he is with Bruce, but they have fought together twice now, surely that counts for something, surely-

“I trust him,” he blurts, and yes. This is right. Tony hadn’t even known until he said it, but the knowledge sinks into his bones and settles there like something he has always known, a certainty he doesn’t have words for.

Bucky holds his gaze for a moment longer, then he nods.

“Buck-”

“We’ll think about it,” Bucky promises, the wariness seems to have left his eyes. “It’s enough that he means so much to you, Stark. I- we appreciate this.”

Somewhat stunned, Tony finds himself at a loss for words. This is so very nearly what he wanted and yet it’s all wrong. This isn’t how things are supposed go, for Bucky to side with him and for Steve to stand immovably in opposition. He wanted to make amends with Steve, to bring the _Avengers_ back together, but for all his sentimentality, he doesn’t seem to have fixed anything. Tony shoves himself away from the kitchen table in sudden aggravation.

“Fine. Let me know when you’ve decided.” He makes a hasty retreat to his lab. There are still questions from the hostage incident he needs to work out, data to analyze. He doesn’t have time to spare for Steve, much less for his friend - Bucky, Sergeant Barnes, the Winter Soldier. What does it matter?

The lights in the lab are still on, spilling out into the corridor like a lighthouse beacon. At the door, Tony pauses. Bruce is at his bench, standing with his back to him. Tony can’t see his face, so he doesn’t know what it is that puts him immediately on alert, but he pauses at the threshold and his hand flies to the activation button for his Iron Man suit.

“Bruce?” he asks cautiously, voice pitched low.

Bruce startles and turns. “Tony,” he says, and there is an odd note to his voice. He steps away from the bench so Tony can see what’s spread out across it: the black box disassembled into six square pieces.

“What did you find?” Tony asks. The contents will surely be key to this whole situation, the reason why four gunmen would threaten civilians in the middle of Times Square in broad daylight.

Bruce shakes his head and Tony gets a terrible premonition in his gut.

“Tony," he says, sounding utterly bewildered. "The box was empty.”


End file.
